The use of audio devices structured to be at least partly inserted into one or both ears of a user (i.e., so called “in-ear” audio devices or “intra-aural” audio devices) to enable audio to be acoustically output to one or both ears of a user has become commonplace, especially with the widespread use of digital audio recording playback devices (e.g., MP3 digital file players) and two-way wireless communications devices (e.g., cell phones and personal data assistant devices incorporating cell phone capabilities). However, difficulties remain in providing in-ear audio devices that fit comfortably in users' ears, and that fit well enough to cooperate with the structure of the ear to provide a high quality of sound in the acoustic output of audio. Much of the reason for this difficulty is that no two ears have shapes that are ever exactly alike, such that an in-ear audio device that is able to provide a good fit in an ear of one user may be unable to do so in an ear of another user.
One well known solution is to provide in-ear audio devices with a selection of removable hollow ear couplings that are each shaped and/or sized differently to enable the in-ear audio devices to be used with different dimensions and shapes of ears. However, as is well-known to the users of in-ear devices, achieving a good fit can be difficult even with in-ear audio devices that are supplied with a relatively extensive assortment of hollow ear couplings from which to choose.